1. Field of the Invention:
The present invention relates to handle assemblies for turning rotational shafts such as valve stems and in particular to such handle assemblies that include latching means to lock rotational movement in predetermined specific positions.
2. Relation to the Prior Art:
It has been common to provide control handles with stops at "off" and "on" locations. It has also been common to provide spring-loaded detents at several locations. Frequently there is a need to prevent accidental or negligent turning of a control. When dealing with dangerous chemicals or electricity, there can be a safety hazard. Costly production losses can occur due to a control misadjustment. There is also a need to lock controls against malicious mischief and theft.